COMPARATIVE ASPECTS OF MANUFACTURING TECHNIQUES FOR THE FRAME OF AN ARCH PROSTHESIS

Abstract

The technologies of manufacturing the arch of the arch prosthesis are constantly being refined and updated. The introduction of digital technologies, in particular CAD/CAM, into orthopedic dentistry has led to a qualitatively new level of precision in the planning, modeling and direct fabrication of the arch of the arc prosthesis. The purpose and tasks of this work was a comparative analysis of the laboratory stages of the production of the arc prosthetic framework on the classical and CAD/CAM technology. The object and methods of research. The object of the study was the technology of manufacturing arch arches prosthesis by the method of comparative analysis. To achieve the goal and to solve the tasks on the models of the same patient M., 42 years old, the laboratory stages of the manufacture of arch arches have been carried out: the first - on the classical technology, and the second - using CAD/CAM. Classical construction technology arch prosthesis well described in the literature and does not require detailed exposition. Making frame for CAD/CAM technology is as follows: 1) receiving an anatomical imprint and making a personal spoon; 2) obtaining a functional imprint using special matte imprint materials;3) scanning of a functional imprint after its spraying with a special light reflecting spray; 4) converting the received scanning results into digital format, obtaining a virtual model and installing it in a virtual articulator; 5) studying the computer model of the jaw in the visual parallelogram and determining the optimal way of applying the prosthesis. The program analyzes the inclination and location of the supporting teeth by the method of selection, while showing the size of the retention zone; 6) the next step is to prepare the model for duplication; 7) virtual duplication of the model; 8) simulation of the framework of the future bell-proof prosthesis on the virtual model. One of the peculiarities of this stage is the primary virtual arrangement of artificial teeth in a virtual articulator, and then the automatic modeling of the frame, taking into account the density of interdental contacts; 9) the simulated virtual skeleton is printed from ashless plastics on a 3D printer; 10) a frame made of ash-free plastic is packed in a cuvette and casting is carried out. Results of the research and their discussion. Planning and designing an arc prosthetic design with the help of specially designed computer programs avoids the subjective factor. The study of the model in a virtual parallelogram helps to choose the most optimal way of introducing an arc prosthesis, makes it possible to visually see the volume of the retention zone. If the crown of the reference tooth has an imperfect shape or an insufficiently expressed equator, the program itself will prompt in which direction it should be corrected by making a crochet, which is a significant advantage over classical technology. Proponents of common technology may be sceptical of the fact that the same manipulation can be performed without the use of digital technologies. But, this will be pretty rough and rough, without specifying the required amount of polishing the hard tooth tissues and visualizing the desired shape of the future crown design. In order to maximize the restoration of chewing efficacy and achieve a high aesthetic effect, an artificial teeth are first arranged in a virtual articulator, and then the automatic modeling of the frame. The patient has the opportunity to pre-see the appearance of the future prosthesis and to assess the aesthetic location of the fixation elements. Using for casting a printed on a 3D printer with a frame made of ashless plastic increases the accuracy of the boarding of the frame on the support teeth, which is better than casting on the ceramic model. Conclusions. By comparing the results of each stage of planning, designing and fabricating the arch of the arc prosthesis, it is safe to assert that the CAD / CAM technologies have a number of advantages and are promising for use in arc prosthetics.

Keywords

• CAD/CAM technology
• arc prosthesis